Birdwatch News Archive

Kittiwakes at their breeding ledges have been a scarce sight this year. Photo: Andy Hay (rspb-images.com).

Kittiwake crash

Posted on: 23 Aug 2012

Kittiwake numbers have suffered a dramatic reduction this summer, on top of their already worrying decline, due to a crash in the sand-eel population.

Dramatic changes in the marine environment fuelled by climate change are believed to be responsible for the collapse in numbers of the pelagic, cliff-nesting gull species. Its population has more than halved since the mid-1980s and populations in Scotland have crashed by almost two thirds. Figures from JNCC (Joint Nature Conservation Committee) show that between 1986 and 2011, Kittiwakes declined by 55 per cent over the whole United Kingdom, equivalent from 31 per cent in England, 66 per cent in Scotland and 26 per cent in Wales.

Early reports of seabird nesting performance from this summer indicate continuing problems for the Kittiwake population, with one Scottish breeding colony now extinct and others predicted to disappear within three years. Counts of the average number of chicks per nest also seem to be reducing too. These declines are being linked to changes in the marine environment.

Euan Dunn, is the RSPB’s head of marine policy. He said: “It now seems beyond doubt that the decline of the Kittiwake is being driven by a slump in the availability of sand-eels, a staple food for this and many other seabirds. It is almost certain that the crash of sand-eels is linked to the warming of the sea and subsequent changes in plankton availability. In other words, changes at the microscopic level are wreaking havoc at the other end of the food chain.”

Although one of the world’s most abundant seabirds, Kittiwake is declining at an alarming rate, particularly in Orkney and Shetland where around one-fifth of the UK population return to breed each year. Counts by RSPB Scotland and the Joint Nature Conservation Committee (JNCC) of Orkney’s “seabird cities” revealed a staggering 82 per cent decline in breeding pairs of Kittiwake in just over a decade. Populations on the Orkney mainland fell from nearly 11,000 pairs in 2000 to under 2,000 this year.

At Mull Head on the Orkney mainland, the once bustling cliffs were empty this year as Kittiwakes failed to return to the colony to breed. The cliffs at Costa Head and Birsay held less than 200 breeding pairs while three other colonies hung on by a thread with fewer than 90 nests each, indicating possible local extinction within the next three years. RSPB Scotland’s Marwick Head reserve hosted most of the breeding Kittiwakes with 1,134 pairs. However, numbers were 75 per cent lower than in 1999, when there were 5,400 pairs nesting.

Doug Gilbert, RSPB Scotland Head of Reserves Ecology, said: “The counts this year are deeply shocking, especially the loss of kittiwakes at Mull Head. We know that Kittiwakes in other parts of Orkney are equally affected and to think of Orkney without thriving colonies of these fantastic birds is a sad prospect.”

Elsewhere, the species is experiencing mixed fortunes. RSPB Scotland’s Sumburgh Head reserve in Shetland reported a poor year with only a small number of chicks fledging. In contrast, the Kittiwake colony at Troup Head RSPB on the Moray Firth has experienced its best season in years, with over 500 chicks fledging. Fowlsheugh RSPB on the Aberdeenshire coast reported a halt in the long-term decline in Kittiwake numbers, after the colony had been in freefall; 20 years ago there were over three times as many nests, but the number of chicks raised in recent years is encouraging.

Euan Dunn added: “Seabirds remain largely unprotected at sea and have been marginalised in the identification of new Marine Protected Areas. This obvious gap needs to be filled if we’re going to prove we’re serious about protecting threatened marine wildlife. It is vital to maintain the current tight restrictions on the North Sea’s industrial fishery for sand-eels to ensure it doesn’t add to the wider pressures on sand-eel stocks.”

In other parts of Kittiwake’s range, there is evidence from Iceland, Greenland and Norway of its population declining. In 2008, Kittiwake was added to an international watch list of threatened species, under the Ospar (Oslo-Paris) Convention, set up to protect the marine environment of the north-east Atlantic.